This invention relates to the field of wheel suspensions, and particularly to wheel suspension systems that independently support the wheels of a vehicle in which a wide and low cargo floor is desired. This invention is an improvement to the wheel suspension systems described in my earlier patents, namely, U.S. Pat. No. 4,878,691, issued on Nov. 7, 1989; U.S. Pat. No. 4,934,733, issued on Jun. 19, 1990; U.S. Pat. No. 5,016,912, issued on May 21, 1991; U.S. Pat. No. 5,275,430, issued on Jan. 4, 1994; U.S. Pat. No. 5,839,750, issued on Nov. 24, 1998; U.S. Pat. No. 6,398,251, issued on Jun. 4, 2002; U.S. Pat. No. 6,428,026, issued on Aug. 6, 2002; U.S. Design Pat. No. D485,787, issued on Jan. 27, 2004; and U.S. Publication No. US-2002-0105170, published Aug. 8, 2002; all incorporated herein by reference.
For a variety of reasons, it is frequently desirable to have the cargo floor of a trailer, van or similar vehicle as low as reasonably possible. A low floor provides for more efficient transportation of cargo, giving a vehicle more useable, internal space for given exterior dimensions. Also, a low floor placed close to the road surface makes for easier access to the vehicle. These and other advantages of a low cargo floor have motivated various proposals for low vehicle floors.